The Fluke CXT170 extreme case is unbreakable, watertight, airtight, dustproof, chemical resistant and corrosion proof. The CXT170's buoyancy allows it to float in salt water with a 3.6 kg (7.94 lb) load. This Fluke extreme case includes an automatic purge valve for quick equalization after changes in atmospheric pressure. A 6.4 mm (0.25 in) neoprene O-ring and ABS latches are used to create an excellent seal.